India is often referred to as a subcontinent because it
a-a peninsula ethnically and culturally isolated from the rest of asia
b-a peninsula separated from the rest of asia by mountains
c-larger than some continents
d-larger than most nations

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).